Image sensors are integrated circuit devices that include a plurality of sensor elements or pixels formed in a semiconductor substrate. The sensor elements are used for sensing a volume of exposed light projected towards the semiconductor substrate. For image sensors, a desire exists to advance quantum efficiency (QE) when pixel size is shrunk down. QE refers to the response with which the image sensor converts light to electrons within each pixel. Various techniques are used to form image sensors and to improve QE and sensitivity. For example, organic materials are used to form image sensors. However, in the existing image sensors with organic materials, existed are various issues that include high dark current and low power conversion efficiency.
Therefore, what is needed is a structure of an organic image sensor and a method making the same to address the above issues.